Amine modified magnetic polystyrene for extraction of drugs from
urine samples
Shakiba Zeinali, Maryam Maleki, Habib Bagheri
Journal of Chromatography A, 1602 (2019) 107-116
doi: 10.1016/j.chroma.2019.06.007
Polystyrene is one of the best candidates as the extracting medium due to its high stability in different media and acceptable extraction capability. However, the hydrophobic nature and low wettability
of polystyrene limits its application to non–polar analytes. To resolve this limitation, in this project,
amine groups were chemically attached to the surface of magnetic polystyrene. The resulting hydrophilic
magnetic particles were expected to be capable of extracting both polar and non–polar analytes.
Non–steroidal anti–inflammatory drugs (NSAIDs) were chosen for testing the applicability of modified
magnetic polystyrene according to the importance of their analysis and also their wide polarity range.
Major parameters associated with the extraction procedure were optimized using central composite
design (CCD) method and pH 3, extraction time of 15 min, desorption volume of 350 μL and desorption
time of 4 min were chosen as optimized values. Under these conditions, figures of merit were calculated including: linear dynamic range (0.5–1000 μg L-1), linear equation and limits of detection (0.1–3
μg L-1). To investigate the method precision, inter–day, intra–day and synthesis–to–synthesis relative
standard deviation (RSD) were studied (<12%). All studies were conducted using blank urine samples
spiked with aspirin, salicylic acid, ibuprofen, diclofenac and mefenamic acid. Naproxen was chosen as
the internal standard and high–performance liquid chromatography–UV–Vis (HPLC–UV) was employed
for the subsequent determination after extraction. To evaluate the applicability of the method for real
sample analysis, urine samples from patients under treatment were analyzed and acceptable results were
obtained. The aminated magnetic polystyrene revealed superior extraction efficiency, much higher than
polystyrene before functionalization. In addition, hospital wastewater sample was tested and acceptable
extraction efficiencies were obtained.